Folding stairs having hinge mechanisms with varied rotation axis are known, as for example hinge mechanisms according to Polish patent No. 199927, providing folding stairs with closing flaps covering the door frame opening, where this flap also serves as a supporting structure for stair segments which are attached thereon. Because such flap functions as a supporting structure, the flap must be properly reinforced, so that it can sustain loads from both the weight of the stair segments and the weight of the users going up or down these stairs.